I know with many machines especially the more expensive ones, they will have a stitch counter in them. If you look closely at the warranty, it will state something like " for home use only" As industrial machines meant for business, usually are built out of more long lasting metal parts, I have worn out one of the plastic parts on my viking D1, that I was replaced but not covered under the warranty because I just stitched it right down. My repair man told me that if the stitch count is really high, he will question the owner if they had been using the machine in a business.....A lot of the cheaper machines, are just meant to be replaced when they go down it seems.